First chapter from EU COST Action "Biochar" final publication published!

Recently, several milestone publications of biochar have been published, among others, the second issue of "Biochar for Environmental Management" (2015) and this year, "Biochar in European Soils and Agriculture" (2016). Now we are happy to announce that the first chapter of the final publication of the EU COST Action "Biochar as option for sustainable resource management" (2017) is just today published in the journal Journal of Environmental Engineering and Landscape Management.


In the first chapter, Biochars in soils: towards the required level of scientific understanding by Priit Tammeorg and 32 co-authors, we identified key priorities in biochar research for future guidance of sustainable policy development . The current level of scientific understanding (LOSU) regarding the consequences of biochar application to soil were explored. Five broad thematic areas of biochar research were addressed: soil biodiversity and ecotoxicology, soil organic matter and greenhouse gas (GHG) emissions, soil physical properties, nutrient cycles and crop production, and soil remediation. The highest future research priorities regarding biochar’s effects in soils were: functional redundancy within soil microbial communities, bioavailability of biochar’s contaminants to soil biota, soil organic matter stability, GHG emissions, soil formation, soil hydrology, nutrient cycling due to microbial priming as well as altered rhizosphere ecology, and soil pH buffering capacity. Methodological and other constraints to achieve the required LOSU are discussed and options for efficient progress of biochar research and sustainable application to soil are presented. This, as well as the forthcoming chapters in that final publication of the COST action will be Open Access, so free to download and distribute!

3rd Finnish Biochar Seminar

The 3rd Finnish Biochar Seminar was successfully held in Viikki, Helsinki, on 25 November 2016!

Many thanks for all the participants and to City of Helsinki for the support!

See the proceedings here:
3rd Finnish Biochar Seminar

The city of Stockholm pioneers in the biochar use and production

Last August I had chance to visit the city of Stockholm and hear about their biochar efforts. It is really impressive what they have succeeded within past five years or so, much thanks to the enthusiasm of Mr. Björn Embrén from City of Stockholm’s Landscaping Department.

It all started more than 15 years ago, when Björn noticed that trees perform poorly in compacted urban soils. It was costly to plant trees, fertilize and take care of them- and if they were not doing well, they had no landscaping value and they had to be replaced. On the other hand, there were trees growing on sides of rock walls or on top of old chimneys, where rarely any soil existed- so it was not soil that the roots needed but effective aeration (CO2 away and oxygen to the roots), moisture and nutrients.

They then started experimenting with structural soils, a planting holes with a layer of big, 3-7 cm diameter rocks in the bottom and soil washed between the rocks.

This was a success, and as the next step, in 2009, they switched to using biochar instead of soil for all of their urban tree planting projects. They have found that the main advantage of biochar for urban tree projects over other soil amendments is that it resists compression and compaction.  The crushed stones and biochar mix results in an improved porosity in the soil (roughly 40%).  Increased porosity facilitates better gas exchange, permeability leading to improved root penetration.

Schematics from Björn Embrén.

A further improvement on their methods has been to have the biochar and stones delivered pre-mixed.  They have found that this saves up to 25% in time and labour costs.  The preferred biochar particle size of the biochar is between 1 – 10 mm and currently they recommend approximately 2.25 cubic meters of biochar   for each urban tree (likely mixed with rocks already, but still quite a lot!).  This explains why loads of biochar from Europe have been shipped to Stockholm, mostly from Germany but also from  RPK Hiili OY (Mikkeli, Finland).

In order to be truly sustainable, however, a goal of using locally produced biochar from underutilized biomass was set. To attain this goal the City of Stockholm initiated the Stockholm Biochar Project with the objective of producing both biochar and renewable energy using urban green waste collected from municipal parks as well as city residents.  This particular biomass is often difficult to dispose of and very much underutilized.
The Stockholm Biochar Project team succeeded in winning one of the five coveted prizes of the 2014 Mayors Challenge funded by Bloomberg Philanthropies and the EUROCITIES organization which netted them 1 million euros to be used to set up their initial pilot plant.

We visited the plant last summer and according to latest news in the Biochar journal, it will produce its first tons of biochar within a few months from now, in summer 2016! The pilot plant will start from producing 300 tonnes of biochar per year and at full scale, will reach 1,500 tonnes per year. The heat generated during production will be added to a local or district heating network. Biochar will be used both by city residents and by city landscapers in public parks and urban tree beds. Probably we will soon see many other cities following the example and getting their green waste recycled, carbon fixed and trees happy!

Read more and see images at: https://www.biochar-journal.org/en/ct/77-Planting-Urban-Trees-with-Biochar